The invention relates to the field of spacecraft design and space debris removal system. More particularly, the present invention relates to a dragsphere for removing orbital space debris.
Over the past several decades, many systems have been launched into orbit about the earth. Some of these systems, including large spacecraft, have long passed useful operating lives and have effectively become space debris. Defense surveillance program have deployed satellites in high geosynchronized orbits. The deployed satellites have operational fuel for maintaining the satellite in the geosynchronized orbit and reserve fuel to deorbit a spacecraft after operational usefulness into an outer supersynchronized burial or disposal orbit. The spacecraft could have extended life for orbit maintenance if the reserve fuel could be used for orbit adjustment.
Currently, designs for microsatellites and picosatellites promise the deployment of many small orbiting satellites that would further congest space orbits providing an ever increasing need to remove from orbit space debris. Other types of waste debris, such as jettison hardware waste, have also been collecting in orbit about the earth. These objects may travel at extremely high speeds representing serious threats to operating spacecraft in orbit. Over time, gravity can affect the orbits of space debris causing ever shifting orbits presenting a compounding threat and need for elaborate collision avoidance methods. Presently, there are thousands of space debris objects being tracked so that planners can place a new system in an unobstructed orbit or that operators can maneuver space systems to avoid collision with space debris objects. Presently, there are no realistic means available to remove debris by deorbiting or transorbiting a piece of orbiting debris. As such, there exists a serious threat to existing operating spacecraft, which threat is continually increasing. Confronted with an every increasing risk of collision, some system planners have proposed attaching a sacrificial propulsion system that then thrusts the debris out of an existing orbit to either deorbit the debris into the atmosphere where the debris deorbits from a low earth orbit into the atmosphere and burns up, or transorbit the debris from high earth orbit to an outer waste orbit by thrusting the debris to the outer waste orbit. Such proposed space debris attaching systems have autonomous navigation, ranging, thrusting, and close in navigation capabilities. However, such proposed systems do not have suitable means for attaching and deorbiting the space debris. These and other disadvantages are solved or reduced using the invention.
An object of the invention is to provide a system for removing space debris.
Another object of the invention is to provide a system for removing space debris from a low earth orbit into the atmosphere.
Yet another object of the invention is to provide a system for removing space debris from a high earth orbit into an outer waste orbit.
Still another object of the invention is to provide a system for removing space debris using an inflatable controlled grabber for grabbing the debris.
A further object of the invention is to provide a system for removing space debris using an inflatable controlled grabber for grabbing the debris and using a deorbiting means for deorbiting or transorbiting the debris.
The invention is directed to a deorbiting spacecraft for the removal of space debris. The deorbiting spacecraft includes conventional components such as having ranging sensors, navigation processors and propulsion systems. The preferred form is directed to a single deorbiting spacecraft, but multiple like spacecraft could be bundled together for deploying a plurality of like spacecraft when several debris objects are to be deorbited. The deorbiting spacecraft includes a deployable grabber and a deorbiting means referred to as a deorbitor. In the preferred form, the deployable grabber is an inflatable grabber, and the deorbiting means is a dragsphere for removing debris from a low earth orbit into the atmosphere where the debris eventually burns up, or the deorbitor includes a thruster for thrusting the debris out of a high earth orbit into an outer waste orbit. In another form, the dragsphere is propelled by the solar wind pushing upon the dragsphere so as to transorbit the debris from a high earth orbit to an outer disposal orbit.
The deorbiting spacecraft inflatable grabber has deployable inflatable fingers with a tensioning mechanism for gripping the debris. The inflatable fingers are inflated to extend from the deorbiting spacecraft in a plurality of respective directions. After inflation when the deorbitor has made a close approach to the debris, the inflatable fingers are then retracted by articulated flexing so as to grab the debris object. In the preferred form, the tensioning mechanism is a mix of motors and tension lines extending through loop eyes along the extending inflated fingers, so that, the motors are controlled to pull and release the tension lines in a controlled manner, to bend the inflatable flexible fingers to surround and grab the debris object. After grabbing, the deorbiting spacecraft then deorbits the debris using the deorbitor. The deorbitor is preferably a fuel efficient inflatable dragsphere used for atmospheric dragging and deorbiting low earth orbit debris into the atmosphere or dragging and deorbiting by solar wind forces high earth orbit debris into the outer supersynch disposal orbit disposal orbits, or is preferably a thruster for thrusting and transorbiting the debris from the high earth orbit to the outer disposal orbit. The dragsphere is a deployable high drag device such as a balloon or rigidizable sphere. This dragsphere enables deorbiting the debris by a simple mechanism instead of attaching a propulsion and guidance system to forcefully deorbit by large thrust in a short period of time. These and other advantages will become more apparent from the following detailed description of the preferred embodiment.